PURPOSE: To provide excellent characteristics in a wide temperature range in a rotating angle detecting device in which a light position detecting element and a Hall element are used.

CONSTITUTION: The rotating angle detecting device is provided with a light putting-out means to put out an irradiation light source 31 to a light position detecting element 11, a measuring means to measure the dark current of the light position detecting element 11 while the light source is put out, and a comparing means to compare the dark current with a set value. Also it is provided with a selector means which, when the dark current exceeds a set value, is switched over to a detector 7 using the light position detecting element 11, and when the dark current is below the set value, switched over to a detector 8 using a Hall element.